A magnetic recording technology that utilizes magnetization states to perform the recording and reproduction of information has features of large capacity, high speed, and low cost. These days, from a viewpoint of further improvement in recording density etc., methods are proposed in which recording density is improved by manipulating and detecting magnetization using a magnetic resonance, which is a response of a magnetic material to a high-frequency magnetic field with a specific frequency.
For example, a microwave-assisted magnetic recording system is a technology in which a high-frequency magnetic field near a resonance frequency of a magnetic recording medium is applied to the medium and at the same time a magnetic field is applied, and a magnetization reversal occurs by a magnetic field weaker than the coercive field.
In such magnetic recording, further improvement in recording density is desired.